Pneumatic convertible relay capable of performing logic functions

ABSTRACT

A pneumatic convertible relay capable of performing logic functions has a relay body that includes a control mechanism for moving a valve member. The valve member includes a slideable stem with a foot on one end and a head on the other end. For a normally open construction the head carries an angular valve head seal and in normally closed construction the foot also carries a seal for controlling flow between a mating seat and a passage along the slidable stem. The valve body is in three sections and includes an inlet, an outlet, an exhaust, and two control openings. The control mechanism includes a diaphragm positioned to act on the foot of the valve member under control of pressure applied to either of the control openings. A slideable shuttle provides alternative operation. The valve is convertible from a normally open construction to a normally closed construction by changing the position of a passage in a valve seat to connect either the inlet to the outlet or the exhaust to the outlet and the position of the annular valve seal, while the other components remain the same. This invention relates to improvements in pneumatic relays with logic functions. There are many types of pneumatic relays known in the art which allow for various combinations or sequences of control. These relays may be generally classified in two categories. One category of prior art relays are those capable of performing logic functions according to their mode of connection to various control openings. These relays allow the construction of predetermined automatic controls with the help of a reduced number of relays. However, these relays are relatively complicated and complex as well as expensive. Another type of relay is that capable of performing only one basic logic function. These relays are of relatively simple construction and low cost; however, allow only one logic function to be accomplished, e.g., the inhibit function. The association of these relays, according to the rules of Boolian algebra allows several complex logical functions to be performed. In order to simplify the construction of a network to provide a desired logic function and reduce the cost of it, it is preferable to use only two elementary cells or relays. One, normally open (n/o) corresponds to a negation or inhibit function. The other, normally closed (n/c) corresponds to an affirmative function. Of course, normally open relays as well as normally closed relays are known in the art. However, these known relays have very different functions, and cannot be constructed form identical elements. This invention provides a pneumatic relay capable of being constructed from identical components which may take the form of either normally open or normally closed with minor variations. The relay, in accordance with this invention, allows provision of all the logic functions and the construction of a hazard free memory. Consequently, this invention relates to a pneumatic relay with logic functions characterized in that, inside the relay&#39;&#39;s body, it includes a control assembly with at least two access openings. A valve slide member has a foot On one end and a head on the other end provided with a valve seal, and the valve member is guided in the valve body. A passage extends in the valve body along the stem of the slideable valve member, and the valve seal on the valve head controls the communication between an inlet chamber and this passage, which may be in the form of a groove in the stem of the valve member. In a normally closed construction, an outlet port is in communication with the groove passage in the valve stem, and the valve head seal closes this passage from the inlet chamber in normal condition. In the normally open construction, a passage is provided in the valve seat, normally connecting the inlet and outlet chambers, while the groove passage in the stem of the valve member is normally connected only to exhaust, but when the control mechanism changes the position of the valve, the valve head closes the passage between the inlet and outlet chambers, and connects the outlet chamber to exhaust through the groove in the valve stem.

United States Patent Inventor Gerard C. C. J. Delrue Pontarlier, FranceAppl. No. 799,305

Filed Feb. 14, 1969 Patented Sept. 14, 1971 Assignee ScovillManufacturing Company Waterbury, Conn.

PNEUMATIC CONVERTIBLE RELAR 611ml: 0 or PERFORMING LOGIC FUNCTIONS3,385,322 5/1968 Brandenberg l37/625.66 3,389,720 6/1968 Brandenbergl37/625.66

, FOREIGN PATENTS 73,298 l/1894 Germany 251/367 Primary Examiner-HenryT. Klinksiek Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT:A pneumatic convertible relay capable of performing logic functions hasa relay body that includes a control mechanism for moving a valvemember. The valve member includes a slideable stem with a foot on oneend and a head on the other end. For a normally open construction thehead carries an angular valve head seal and in normally closedconstruction the foot also carries a seal for controlling flow betweena' mating seat and a passage along the slidable stem. The valve body isin three sections and includes an inlet, an outlet, an exhaust, and twocontrol openings. The control mechanism includes a diaphragm positionedto act on the foot of the valve member under control of pressure appliedto either of the control openings. A slideable shuttle providesalternative operation. The valve is convertible from a normally openconstruction to a normally closed construction by changing the positionof a passage in a valve seat to connect either the inlet to the outletor the exhaust to the outlet and the position of the annular valve seal,while the other components remain the same.

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PNEUMATIC CONVERTIBLE RELAY CAPABLE OF PERFORMING LOGIC FUNCTIONS Thisinvention relates to improvements in pneumatic relays with logicfunctions.

There are many types of pneumatic relays known in the art which allowfor various combinations or sequences of control. These relays may begenerally classified in two categories.

One category of prior art relays are those capable of performing logicfunctions according to their mode of connection to various controlopenings. These relays allow the construction of predetermined automaticcontrols with the help of a reduced number of relays. However, theserelays are relatively complicated and complex as well as expensive.

Another type of relay is that capable of performing only one basic logicfunction. These relays are of relatively simple construction and lowcost; however, allow only one logic function to be accomplished, e.g.,the inhibit function.

The association of these relays, according to the rules of Boolianalgebra allows several complex logical functions to be performed.

In order to simplify the construction of a network to provide a desiredlogic function and reduce the cost of it, it is preferable to use onlytwo elementary cells or relays. One, normally open (n/o) corresponds toa negation or inhibit function. The other, normally closed (n/c)corresponds to an affirmative function.

Of course, normally open relays as well as normally closed relays areknown in the art. However, these known relays have very differentfunctions, and cannot be constructed form identical elements. Thisinvention provides a pneumatic relay capable of being constructed fromidentical components which may take the form of either normally open ornormally closed with minor variations. The relay, in accordance withthis invention, allows provision of all the logic functions and theconstruction of a hazard free memory.

Consequently, this invention relates to a pneumatic relay with logicfunctions characterized in that, inside the relays body, it includes acontrol assembly with at least two access openings. A valve slide memberhas a foot on one end and a head on the other end provided with a valveseal, and the valve member is guided in the valve body. A passageextends in the valve body along the stem of the slideable valve member,and the valve seal on the valve head controls the communication betweenan inlet chamber and this passage, which may be in the form of a groovein the stem of the valve member. In a normally closed construction, anoutlet port is in communication with the groove passage in the valvestem, and the valve head seal closes this passage from the inlet chamberin normal condition. In the normally open construction, a passage isprovided in the valve seat, normally connecting the inlet and out letchambers, while the groove passage in the stem of the valve member isnormally connected only to exhaust, but when the control mechanismchanges the position of the valve, the valve head closes the passagebetween the inlet and outlet chambers, and connects the outlet chamberto exhaust through the groove in the valve stem.

The invention will be further understood by referring to the followingdescription by way of a nonlimiting example and the attached drawings,in which:

FIG. 1 is a sectional elevation view of a relay in accordance with thisinvention constructed as a normally open relay;

FIG. 2 is a sectional elevation view of a relay in accordance with thisinvention constructed as a normally closed relay;

FIG. 3 is a partial sectional view of an inlet or admission chamber as avariation;

FIG. 4 is another modification of variation of the admission or inletchamber;

FIG. 5 is a semibottom plan view of the relay of this invention;

FIG. 6 is a side elevation view of the relay according to thisinvention;

FIG. 7 is a diagrammatic view of a normally closed relay;

FIG. 8 is a diagrammatic view of a normally open relay;

FIG. 9 is a diagrammatic view of a memory incorporating prioritycancelling construction by assembling two relays of this invention;

FIG. 10 is a diagrammatic view of a memory with priority inscriptionconstructed by two relays of this invention; and

FIG. 11 is a diagrammatic view of a memory with priority cancellingconstructed of two relays of this invention.

Referring to FIG. 1, a relay in accordance with this invention isconstructed as a normally open relay. The relay body includes the threejuxtapositioned sections, 1, 2 and 3. Section 1 includes an inlet oradmission port A. Section 2 includes an outlet or exit port S and acleansing or exhaust port P. Section 3 includes two control ports B andC, also see FIGS. 5 and 6.

These various ports A, S, B, and C may be provided with metal ferrules 4for allowing the relay to be positioned and held in a circuit by simplepiping or tubing'or other connections. As shown in FIGS. 5 and 6 theseports are all located on the same side of the relay body.

Inside the relay body a valve slide member 5 includes a foot 6, a stem 7and a head 8. The head 8 includes an annular seal 9 which bears againsta seat 11. A membrance 10 acts as a spring to force the valve seal 9against the seat 11, and is provided with an aperture 12 providingcommunication between admission port A and admission chamber 13 in whichthe head 8 moves.

Holes 14 are provided in the seat 11 and these place an admissionchamber 13 in communication with exit or outlet chamber 15 and theoutlet port S. The valve head seal 9 controls communication betweenadmission chamber 13 and one or several grooves 16 provided along thestem 7. These grooves open into chamber 17 which is connected to theexhaust cleansing port P and in which the foot6 moves. A ring sealfluid-blocking member 18 blocks communication between the passageprovided by groove 16 and the exit chamber 15.

The control mechanism is provided in section 3 of the relay body andincludes a membrane 19 which provides a wall of chamber 17 underneaththe foot 6 and divides chamber 17 from control chamber 20. The twocontrol access ports B and C are connected into control chamber 20through a passage which includes a selection plug 21. This circuitselector performs an OR function. That is, with pressure at control portB, the selector shuttle 21 is in the position shown and pressure will beapplied to the chamber 20. Similarly with pressure control port C thisshuttle will be switched and the pressure will be in control chamber 20.When the control plug is in either one of its extreme positions, controlpressure in both ports B and C will mean that the plug will stay in itspresent position due to the differential area exposed to the pressure.

In the absence of pressure in chamber 20 due to no pressure beingapplied at either control port B or C, the valve head is in the positionof FIG. 1, valve head seal 9 seated on seat 11 and the admission Anormally open is connected to the outlet S. The outlet S and outletchamber 15 are, however, isolated from the exhaust port P.

However, if a pressure signal is applied to either one of the controlinlets B or C (or both of them), the membrane 19 is flexed upwardly andmoves against the foot 6 of the valve body 5 upwardly until the head 8forces the membrane 10 against the seat 22 closing off the admissionport A. The outlet S is then in communication with exhaust cleansingport P due to the fact that valve seal member 9 is moved off of its seat11 and communication is afforded to the passages S, 15, l4, l6, l7 andP.

The logic function of this relay is therefore:

The amplification ratio K of the relay under pressure is therefore:

P the the pressure applied to admission chamber A.

F the pressure inside chamber 20 capable of lifting the foot 6 and ofovercoming the mechanical resistance of membrane 19, membrane 12 as wellas the pneumatic force due to pressure P acting on the top surface ofthe valve head 8.

Referring to FIG. 2, which illustrates the modifications necessary toconvert the normally open relay of FIG. 1 to a normally closed relay,the normally closed relay includes all the elements of FIG. 1 with theexception of seal ring 18.

In addition, the seat 11 is not provided with holes such as hole 14 butis solid. With the removal of seal ring 18, the outlet or exit port 5 isin fluid communication constantly with the exhaust or cleansing port P;the communication between the port A and outlet S is blocked by thevalve head seal 9.

In addition, another valve seal in the form condition of valve foot seal23 is carried by the foot 6 to block communication between the passageafforded by grooves 16 and the outlet chamber 17 when the valve member 5is in its uppermost position. This is accomplished by the valve sealmember 23 seating against seat 24 before the head 8 can block theadmission or inlet port A in its uppermost position. This membrane 10 isnever seated against seat 22 due to the length of the seal member 23 andthe inlet A is always open to admission chamber 13. In the normalcondition of the valve, however, further communication is closed, and onswitching of the valve communication is open to the exit yet closed toexhaust.

In the absence of pressure in control chamber the valve seal member 9rests on seat 11' and outlet or exit port S is closed from admissionport A but is in communication with the atmosphere through exhaust holeP.

When, however, a pressure level signal P is applied to either one of theadmission ports B or C (or both of them), the membrane 19 is deformedunder pressure action and contacts the foot 6 to move the valve member 5upwardly until the valve seal 23 seats. The upward movement, however, isstopped before the admission port A is sealed so that the admission portis in fluid communication with the exit 5 and those ports are isolatedfrom the exhaust port P.

The logic function of the normally closed relay of FIG. 2 is therefore:

The relay in accordance with the invention is susceptible of a number ofvariations. We refer for example to FIGS. 3 and 4. Instead of biasingthe valve member 5" to its normal position by a membrane such as 10, itis possible to bias it by a spring 25 as shown in FIG. 3 and utilize avalve seal member 26 to effect the closing of the admission port A.

As shown in FIG. 4, it is possible to eliminate spring 25 and utilizethe pressure from admission port A acting on the head 8" of valve 5 tobias the valve member towards its normal position. Membrane 19 couldalso be removed and foot 6 replaced by a piston having the pressure ofchamber 20 acting on an end wall.

Referring to FIGS. 5 and 6, these figures show the relay body formed ofthree juxtapositioned sections 1, 2, and 3, and held together with acircumferential strap 28 in a groove 27 extending around the assembledsections, see also FIG. 2.

Referring to FIG. 7, the normally closed relay of FIG. 2 isdiagrammatically illustrated and as indicated above, possesses thefunction:

S=A (B+C) which may in particular accomplish the following functions:

Function OR! in which S=l when A=l and when B=1, C is always 0(! is anunused control access).

Function 0R with two accesses in which S=B+C if A=l.

S=T when B or Cor B and C=I.

Function LTwith two accesses. If B=O, S=AC and reciprocally if C=O,S==AB.

Referring to FIG. 8, the normally open relay, illustrated in thisfigure, has the functions:

The function NOR may be realized in which S=E if A=I and C=O (onecontrol access unused).

Likewise, if A=l, the function NOR is obtained in which s=E+E Inhibitionfunctions may also be realized with one inhibiting access or twoinhibition accesses. Of course, all other logic functions may berealized starting from relays in accordance with this invention andcombining the normally closed and normally open elements in accordancewith the rules of Boolians algebra.

Referring to FIGS. 9, l0 and l l, for examples of combining normallyopen and normally closed elements in accordance with this invention. Thememories represented in FIGS. 9 and 10 are each constructed with onenormally open and one normally closed relay of the type shown in FIGS. 1and 2. Their functions are respectively:

A regular memory composed of two normally open relays with two controlaccesses each is illustrated in FIG. 11. This memory has two feedinginlets 1 and 1", and the resulting function is:

The memory of FIG. 11 contains a hazard in its operation. If, forexample, access 1" is fed before access 1', the memory will be entered.If on the contrary, the access 1' is fed before 1", the memory will becancelled. In order to remedy this drawback, recourse may be made to theintroduction of a time delay in the feeding access of 1" of thememories.

By contrast, the memories of FIGS. 9 and 10 have only one feed inlet andthey are absolutely free of hazards at the time the logic assembly isput under pressure.

Although the invention is described in connection with particular formsand constructions, it is understood that it is in no way limited andthat such changes in form or material may be brought about withoutchanging the essence or principle of it.

What is claimed is 1. A pneumatic relay capable of performing logicfunctions, comprising a body having an inlet port, an outlet port, anexhaust port, a pair of spaced control ports, an admission chamber incommunication with said inlet port, an outlet chamber in communicationwith said outlet port, an exhaust chamber in communication with saidexhaust port, said outlet chamber being disposed between said admissionand exhaust chambers, and a control chamber: means for effectingcommunication between said control chamber and said control ports; avalve member slidably mounted within said body, said valve membercomprising a head at one end thereof disposed in said admission chamberfor controlling said inlet port, a stem connected to said head andextending from said admission chamber through said outlet chamber andinto said exhaust chamber, said stem comprising a longitudinal groove onthe outer surface thereof which is adapted to communicate with saidadmission, outlet and said exhaust chambers, a foot connected to saidstem at the other end of said valve member, said foot being disposed insaid exhaust chamber and being adapted to be controlled by the pressurein said control chamber to effect movement of said valve member; andsealing means on said valve member adapted to engage adjacent portionsof said body to control flow through said stem groove and between saidadmission, outlet and exhaust chambers when said valve member is moved,said sealing means comprising a first annular seal on said valve headsurrounding said stem; said body comprising a first seat for said sealsurrounding said valve stem and being disposed between said admissionchamber and said outlet chamber, said first seat having a passagetherethrough for establishing communication between said admissionchamber and said outlet chamber, and a second seal disposed between saidfirst seat and an adjacent body portion for preventing communicationbetween said outlet chamber and said stem groove.

2. The relay of claim I wherein spring means is disposed in saidadmission chamber for engagement with said head to urge it to a positionwherein said seal first is in engagement with said first seat to closecommunication between said admission chamber and said stern groove.

3. The relay of claim 1 wherein said means for efiecting communicationbetween said control chamber and said control ports comprising a passagebetween said control chamber and said control ports, and a shuttle plugmovable in said passage in response to pressure in said control ports.

4. The relay of claim 1 wherein said body is constructed in threesections, one section containing said inlet port, a second sectioncontaining said outlet port and said valve member, and

a third section containing said control chamber and said means foreffecting communication between said control chamber and said controlports.

5. The relay of claim 4 wherein said three sections comprise anencircling groove, and are secured together by a band portion withinsaid groove.

6. The relay of claim 1 wherein said exhaust chamber and said controlchamber are separated by a flexible membrane mounted within said body,said membrane being deformed into engagement with said foot to move saidvalve member in response to pressure in said control chamber.

7. A pneumatic relay capable of performing logic functions, comprising abody having an inlet port, an outlet port, an exhaust port, a pair ofspaced control ports, an admission chamber in communication with saidinlet port, an outlet chamber in communication with said outlet port, anexhaust chamber in communication with said exhaust port, said outletchamber being disposed between said admission and exhaust chambers, anda control chamber; means for effecting communication between saidcontrol chamber and said control ports; a valve member slidably mountedwithin said body, said valve member comprising a head at one end thereofdisposed in said admission chamber for controlling said inlet port, a

stem connected to said head and extending from said admission chamberthrough said outlet chamber and into said exhaust chamber, said stemcomprising a longitudinal groove on the outer surface thereof which isadapted to communicate with said admission, outlet and said exhaustchambers, a foot connected to said stem at the other end of said valvemember, said foot being disposed in said exhaust chamber and beingadapted to be controlled by the pressure in said control chamber toeffect movement of said valve member; and seal ing means on said valvemember adapted to engage adjacent portions of said body to control flowthrough said stem groove and between said admission, outlet and exhaustchambers when said valve member is moved, said sealing means comprisinga first annular seal on said valve head surrounding said stem; said bodycomprising a first seat for said seal surrounding said valve stem andbeing disposed between said admission chamber and said outlet chamber,and a second seat facing said valve foot; said foot having a secondannular seal mounted thereon and surrounding said valve stem, saidsecond seal being adapted to engage said second seat when said foot issubjected to pressure in said control chamber and is moved toward saidsecond seat.

1. A pneumatic relay capable of performing logic functions, comprising abody having an inlet port, an outlet port, an exhaust port, a pair ofspaced control ports, an admission chamber in communication with saidinlet port, an outlet chamber in communication with said outlet port, anexhaust chamber in communication with said exhaust port, said outletchamber being disposed between said admission and exhaust chambers, anda control chamber: means for effecting communication between saidcontrol chamber and said control ports; a valve member slidably mountedwithin said body, said valve member comprising a head at one end thereofdisposed in said admission chamber for controlling said inlet port, astem connected to said head and extending from said admission chamberthrough said outlet chamber and into said exhaust chamber, said stemcomprising a longitudinal groove on the outer surface thereof which isadapted to communicate with said admission, outlet and said exhaustchambers, a foot connected to said stem at the other end of said valvemember, said foot being disposed in said exhaust chamber and beingadapted to be controlled by the pressure in said control chamber toeffect movement of said valve member; and sealing means on said valvemember adapted to engage adjacent portions of said body to control flowthrough said stem groove and between said admission, outlet and exhaustchambers when said valve member is moved, said sealing means comprisinga first annular seal on said valve head surrounding said stem; said bodycomprising a first seat for said seal surrounding said valve stem andbeing disposed between said admission chamber and said outlet chamber,said first seat having a passage therethrough for establishingcommunication between said admission chamber and said outlet chamber,and a second seal disposed between said first seat and an adjacent bodyportion for preventing communication between said outlet chamber andsaid stem groove.
 2. The relay of claim 1 wherein spring means isdisposed in said admission chamber for engagement with said head to urgeit to a position wherein said seal first is in engagement with saidfirst seat to close communication between said admission chamber andsaid stem groove.
 3. The relay of claim 1 wherein said means foreffecting communication between said control chamber and said controlports comprising a passage between said control chamber and said controlports, and a shuttle plug movable in said passage in response topressure in said control ports.
 4. The relay of claim 1 wherein saidbody is constructed in three sections, one section containing said inletport, a second section containing said outlet port and said valvemember, and a third section containing said control chamber and saidmeans for effecting communication between said control chamber and saidcontrol ports.
 5. The relay of claim 4 wherein said three sectionscomprise an encircling groove, and are secured together by a bandportion within said groove.
 6. The relay of claim 1 wherein said exhaustchamber and said control chamber are separated by a flexible membranemounted within said body, said membrane being deformed into engagementwith said foot to move said valve member in response to pressure in saidcontrol chamber.
 7. A pneumatic relay capable of performing logicfunctions, comprising a body having an inlet port, an outlet port, anexhaust port, a pair of spaced control ports, an admission chamber incommunication with said inlet port, an outlet chamber in communicationwith said outlet port, an exhaust chamber in communicatIon with saidexhaust port, said outlet chamber being disposed between said admissionand exhaust chambers, and a control chamber; means for effectingcommunication between said control chamber and said control ports; avalve member slidably mounted within said body, said valve membercomprising a head at one end thereof disposed in said admission chamberfor controlling said inlet port, a stem connected to said head andextending from said admission chamber through said outlet chamber andinto said exhaust chamber, said stem comprising a longitudinal groove onthe outer surface thereof which is adapted to communicate with saidadmission, outlet and said exhaust chambers, a foot connected to saidstem at the other end of said valve member, said foot being disposed insaid exhaust chamber and being adapted to be controlled by the pressurein said control chamber to effect movement of said valve member; andsealing means on said valve member adapted to engage adjacent portionsof said body to control flow through said stem groove and between saidadmission, outlet and exhaust chambers when said valve member is moved,said sealing means comprising a first annular seal on said valve headsurrounding said stem; said body comprising a first seat for said sealsurrounding said valve stem and being disposed between said admissionchamber and said outlet chamber, and a second seat facing said valvefoot; said foot having a second annular seal mounted thereon andsurrounding said valve stem, said second seal being adapted to engagesaid second seat when said foot is subjected to pressure in said controlchamber and is moved toward said second seat.